Conventional ion beam modification methods include methods based on a thin film fabrication and methods based on a surface cleaning process.
As the thin film fabrication methods, there are proposed an ion implantation using a high energy (tens of KeV to a few MeV), an ion beam irradiation, an ion beam sputtering deposition which is implemented by irradiating ionized particles from an ion source generating low energy (0 to a few KeV) particles onto a target for thereby generating a material to be deposited, a multiple ion beam deposition, a process for assisting a thin film fabrication, and an ion-assisted deposition.
In addition, as the surface cleaning methods, there are proposed a surface cleaning which is generated by irradiating energized particles onto the surface of a material and a reactive ion beam etching which is implemented by supplying a reaction gas into a vacuum chamber.
In case of the thin film fabrication using an ion beam, the thin film is fabricated by controlling the relative ratio of the particles between the to-be deposited particles and the assisted ion beam particles. In the case of the cleaning method using the ion beam, a reaction gas is ionized while controlling the occurrence of a plasma and the amount of the reaction gas, thereby implementing a quick surface cleaning, while the cleaning of the conventional wet reaction requires a long time.
FIG. 1 is a schematic view illustrating an earlier-filed (Korean Patent Applns. Nos. 2465/1996, 11994/1996, 11995/1996 and 11996/1196, the disclosures of which are incorporated hereinto by reference) surface modification apparatus which includes an ion source 10 having an ion gun 12 generating an ion beam IB and an assisted ion gun 14 generating an assisted ion beam AB, an ion beam current measuring unit 40 and controller 42 for respectively measuring and controlling the amount of irradiated energized ions, a sample holder 20 holding a sample material 22 the surface of which is to be modified by ions, a reaction gas control apparatus (not shown) having a reaction gas inlet 26 providing therethrough a reaction gas to the sample material 22, a vacuum pump 28 generating a vacuum within an enclosing vacuum chamber 30 in order to facilitate the generation of the ion beams IB, AB.
The apparatus may be implemented in the following ways. First, oxygen is provided as a reaction gas around a polymer material, and argon ions are irradiated onto the surface of the material, thereby generating a hydrophilic functional group, in which an oxygen atom is chemically bonded with a carbon ring, on the surface of the polymer material. In addition, the argon ions are irradiated together with providing the oxygen to the surface of an aluminum nitride AlN, thereby forming a bonding of the AlON and a new material on the surface without affecting the material itself. Accordingly, various problems can be solved due to the variation of inherent properties of surfaces. For example, the adhesion of another material, adsorption, hydrophilic property with water, and surface strength of the material may be changed. In the ion beam assisted reaction, the particle energy having a lower energy band is generally used compared to the earlier deposition methods, and the amount of the ion irradiation is 10.sup.13 -10.sup.18 ions/cm.sup.2, and the amount of the reaction gas is also characterized in that the partial pressure around the material is higher than the total degree of vacuum in the vacuum chamber.
However, in the above-described ion beam irradiating apparatus, only the surface modification by the reaction gas is considered as an important matter. Therefore, the improvement of physical properties and the surface modification characteristic cannot have been obtained by controlling the amount of the reaction gas. Also, the energy of the ion beam applied to a sample material has been controlled by only the ion beam.